#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>
#include <string>


class A
{
public:
	int _a;
};

//class B : public A
class B : virtual public A
{
public:
	int _b;
};

//class C : public A
class C : virtual public A
{
public:
	int _c;
};

class D : public B, public C
{
public:
	int _d;
};

int main()
{
	D d;
	
	d.B::_a = 1;
	d.C::_a = 2;

	d._a = 0;
	d._b = 3;
	d._c = 4;
	d._d = 5;

	return 0;
}